• 대한통합의학회지
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• 제8권1호
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• pp.113-124
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• 2020

Purpose : The purpose of this study was to investigate the effects of exercise intervention combined with 3D visual feedback and motion observation on postural alignment and cerebral cortical activity in subjects with forward head posture (FHP). Methods : The study included 28 participants with FHP, randomly divided into a 3D visual feedback plus motion observation group (n=14) or control group (n=14). The experimental group received corrective exercise combined with 3D visual feedback and motion observation for FHP, three times a week for four weeks. We examined cervical spine radiographs in the lateral standing position with both arms crossed to measure the craniovertebral angle (CVA) and cervical lordosis (CL). Relative alpha (RA) and beta waves (RB) were measured by wireless dry EEG. Results : The CVA value was significantly different between the groups, and the CL value was significantly different only in the experimental group. RA and RB values were not significantly different before and after intervention in the control group. RB values were significantly decreased before and after intervention in the experimental group. Conclusion : Based on the results of this study, we suggest that interventions combined with motion observation and 3D visual feedback may be effective as exercise methods to improve postural alignment and cerebral activity in subjects with FHP. Further research is required to generalize our results on technical supplementation complemented with 3D visual feedback devices.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권3호
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• pp.112-121
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• 2002

This paper describes a new bike system for the postural balance rehabilitation training. Virtual environment and three dimensional graphic model is designed with CAD tools such as 3D Studio Max and World Up. For the real time bike simulation, the optimized WorldToolKit graphic library is embedded with the dynamic geometry generation method, multi-thread method, and portal generation method. In this experiment, 20 normal adults were tested to investigate the influencing factors of balancing posture. We evaluated the system by measuring the parameters such as path deviation, driving velocity, COP(center for pressure), and average weight shift. Also, we investigated the usefulness of visual feedback information by weight shift. The results showed that continuous visual feedback by weight shift was more effective than no visual feedback in the postural balance control It is concluded this system might be applied to clinical use as a new postural balance training system.

• 한국컴퓨터그래픽스학회논문지
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• 제26권3호
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• pp.69-77
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• 2020

본 논문은 3차원 가상환경에서 드로잉할 때, 사용자에게 위치 입력에 대한 피드백을 부여하는 효과적인 방법을 설계하고 그 성능을 측정하여, 피드백을 통해 사용자가 올바른 위치를 입력하는데 도움을 줄 수 있는지 확인하고자 한다. 주어진 선 형상을 핸드-헬드 컨트롤러를 이용하여 따라 그리는 실험에서 사용자에게 위치 입력 오차에 대해 세 단계의 시각, 청각, 촉각 피드백을 각각 제공하고, 어떤 피드백이 가장 효과적인지를 분석하였다. 피드백의 형태에 따른 위치 입력 정확도를 분석한 결과, 피드백은 특정 크기 이상의 입력 오류를 크게 감소시킬 수 있었으며, 시각과 촉각 피드백이 청각 피드백보다 효과적이었다.

• Physical Therapy Rehabilitation Science
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• 제7권3호
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• pp.95-101
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• 2018

Objective: To determine if the provision of visual biofeedback using real-time rehabilitative ultrasound imaging (RUSI) enhances the acquisition and retention of diaphragm muscle recruitment during exercise. Design: Two group pretest posttest design. Methods: Thirty healthy subjects were randomly assigned to the verbal feedback group (VG, n=15) or the visual and verbal feedback group (VVG, n=15). The VG performed breathing exercises 10 times with verbal feedback, and the VVG also performed breathing exercises 10 times with verbal feedback and visual feedback with the use of RUSI to measure changes in diaphragm thickness (DT). For DT, the mid-axillary lines between ribs 8 and 9 on both sides were measured in standing, and then the chest wall was perpendicularly illuminated using a linear transducer with the patients in supine to observe the region between rib 8 and 9 and to obtain 2-dimensional images. DT was measured as the distance between the two parallel lines that appeared bright in the middle of the pleura and the peritoneum. After one week, three repetitions (follow-up session) were performed to confirm retention effects. Intra- and between- group percent changes in diaphragm muscle thickness were assessed. Results: In the VVG, the intervention value had a medium effect size compared to the baseline value, but the follow-up value decreased to a small effect size. In the between-group comparisons, during the intervention session, the VVG showed no significant effect on percent change of DT but had a medium effect size compared to the VG (p=0.050, Cohen's d=0.764). During the follow-up session, retention effect did not persist (p=0.311, Cohen's d=0.381). Conclusions: RUSI can be used to provide visual biofeedback and improve performance and retention in the ability to activate the diaphragm muscle in healthy subjects. Future research needs to establish a protocol for respiratory intervention to maintain the effect of diaphragmatic breathing training using RUSI with visual feedback.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.70.1-70
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• 2001

Recently, research of visual control is getting more essential in robotic application, and acquiring 3D informations from the 2D images is becoming more important with development of vision system. For this application, we propose the effective way of controlling stereo vision tracking system for target tracking and calculating distance between target and camera. In this paper we address improved controller using dual-loop visual servo which is more effective compared with using single-loop visual servo for stereo vision tracking system. The speed and the accuracy for realizing a real time tracking are important. However, the vision processing speed is too slow to track object in real time by using only vision feedback data. So we use another feedback data from controller parts which offer state feedback ...

• 한국산업융합학회 논문집
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• 제17권3호
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• pp.136-144
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• 2014

This paper proposes a new approach to the designed of visual feedback control system based on visual servoing method. The main focus of this paper is presents how it is effective to use many features for improving the accuracy of the visual feedback control of industrial articulated robot for assembling and inspection of parts. Some rank conditions, which relate the image Jacobian, and the control performance are derived. It is also proven that the accuracy is improved by increasing the number of features. The effectiveness of redundant features is verified by the real time experiments on a SCARA type robot(FARA) made in samsung electronics company.

• 전력전자학회논문지
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• 제7권6호
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• pp.524-530
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• 2002

일상 생활에서 반사적인 자세 조절은 정전기관, 시각, 고유수용체 등의 감수체에 의한 구심성 신호가 정전 신경핵에 전달되어 안구운동이나 골격근의 수축을 유발하여 이루어진다. 자세조절기능의 부조화는 오심, 구토, 현기증 등을 초래하여 삶의 의욕을 상실하게 만든다. 본 연구의 목적은 정전기관의 반규관과 이석기관을 선별적으로 자극하기 위한 탈수직축 회전자극 시스템과 수평, 수직, 3D 환경에서 시각자극을 할 수 있는 시운동자극시스템을 개발하여 인간의 자세조절 기능을 평가 하는데 있다. 탈수직축 회전자극 시스템은 편안한 의자와 DC 서보모터로 구동되는 기울임 테이블로 구성되고 PMSM에 의해 제어된다. 그리고 속도 궤환 루프와 위치 궤환 루프를 포함하는 이중 피드백 루프가 서보 제어되는 회전자극시스템에 적용된다. HMD를 이용하여 수평, 수직, 3D 시각자극패턴을 구현 하였고 OKN 자극을 위한 무선시스템과 전기안진 기록계를 이용하여 안구운동을 기록하였다. 이득, 위상, 대칭성은 정전 자극과 시각 자극에 의해 유발되는 안구운동의 분석으로부터 얻어진다.

• 한국CDE학회논문집
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• 제15권2호
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• pp.136-143
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• 2010

Realistic Modeling is to maximize the reality of the environment in which perception is made by virtual environment or remote control using two or more senses of human. Especially, the field of haptic rendering, which provides reality through interaction of visual and tactual sense in realistic model, has brought attention. Haptic rendering calculates the force caused by model deformation during interaction with a virtual model and returns it to the user. Deformable model in the haptic rendering has more complexity than a rigid body because the deformation is calculated inside as well as the outside the model. For this model, Gibson suggested the 3D ChainMail algorithm using volumetric data. However, in case of the deformable model with non-homogeneous materials, there were some discordances between visual and tactual sense information when calculating the force-feedback in real time. Therefore, we propose an algorithm for the Volume Haptic Rendering of non-homogeneous deformable object that reflects the force-feedback consistently in real time, depending on visual information (the amount of deformation), without any post-processing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.103.5-103
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• 2001

This paper presents a visual feedback system that controls a micromanipulator using multiple microscopic vision information. The micromanipulation stations basically have optical microscope. However the single field-of-view of optical microscope essentially limits the workspace of the micromanipulator and low dept-of-field makes it difficult to handle 3D-shaped micro objects. The system consists of a stereoscopic microscope, three CCD cameras, the micromanipulator and personal computer. The use of stereoscopic microscope which has long working distance and high depth-of-field with selective field-of-view improves the recognizability of 3D-shaped micro objects and provides a method for overcoming several essential limitations in micromanipulation. Thus, visual feedback information is very important in handling micro objects for overcoming those limitations and provides a mean for the ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.273-277
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• 2003

A general process of electronic assembly is composed of a series of geometric alignments and bonding/screwing processes. After assembly, the function is tested in a following process of inspection. However, assembly of micro-optic devices requires both processes to be performed in equipment. Coarse geometric alignment is made by using vision and optical function is improved by the following fine motion based on feedback of tunable laser interferometer. The general system is composed of a precision robot system for 3D assembly, a 3D vision guided system for geometric alignment and an optical feedback system with a tunable laser. In this study, we propose a new fast alignment algorithm of micro-optic devices for both of visual and optical alignments. The main goal is to find a fastest alignment process and algorithms with state-of-the-art technology. We propose a new approach with an optimal sequence of processes, a visual alignment algorithm and a search algorithm for an optimal optical alignment. A system is designed to show the effectiveness and efficiency of the proposed method.